package com.xl.utils.file;

import cn.hutool.core.util.ArrayUtil;
import com.xl.enums.FileTimeZoneEnum;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.compress.utils.Lists;
import org.apache.commons.lang3.ArrayUtils;
import org.apache.commons.lang3.StringUtils;
import org.springframework.util.CollectionUtils;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.math.BigInteger;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.attribute.BasicFileAttributes;
import java.security.MessageDigest;
import java.text.DecimalFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.time.Instant;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.util.*;

/**
 * 文件处理工具类
 *
 * @author netshark.kfd
 */
@Slf4j
public class FileUtils {
	/**
	 * 字符常量：斜杠 {@code '/'}
	 */
	public static final char SLASH = '/';

	/**
	 * 字符常量：反斜杠 {@code '\\'}
	 */
	public static final char BACKSLASH = '\\';

	public static String FILENAME_PATTERN = "[a-zA-Z0-9_\\-\\|\\.\\u4e00-\\u9fa5]+";

	//时间格式化标准


	/**
	 * 输出指定文件的byte数组
	 *
	 * @param filePath 文件路径
	 * @param os       输出流
	 * @return
	 */
	public static void writeBytes(String filePath, OutputStream os) throws IOException {
		FileInputStream fis = null;
		try {
			File file = new File(filePath);
			if (!file.exists()) {
				throw new FileNotFoundException(filePath);
			}
			fis = new FileInputStream(file);
			byte[] b = new byte[1024];
			int length;
			while ((length = fis.read(b)) > 0) {
				os.write(b, 0, length);
			}
		} catch (IOException e) {
			throw e;
		} finally {
			if (os != null) {
				try {
					os.close();
				} catch (IOException e1) {
					e1.printStackTrace();
				}
			}
			if (fis != null) {
				try {
					fis.close();
				} catch (IOException e1) {
					e1.printStackTrace();
				}
			}
		}
	}

	/**
	 * 根据文件全路径判断文件是否存在
	 *
	 * @param path 全路径
	 * @return
	 */
	public static boolean exist(String path) {
		File file = getFile(path);
		return file.exists();
	}

	/**
	 * 判断文件是否存在
	 * 存在返回文件
	 *
	 * @param path 根据文件全路径判断文件是否存在
	 * @return
	 */
	public static File existRetFile(String path) {
		File file = getFile(path);
		if (file.exists()) {
			return file;
		}
		return null;
	}

	/**
	 * 判断文件夹存在
	 * 获取文件夹里面所有的文件
	 * 不递归获取
	 *
	 * @param path
	 */
	public static List<File> existDirGetChildFiles(String path) {
		return getDirFiles(path, false);
	}

	/**
	 * 判断文件夹存在
	 * 获取文件夹里面所有的文件
	 * recursion 为false 不递归获取 为true递归获取文件夹下的文件
	 *
	 * @param path
	 * @param recursion
	 * @return
	 */
	public static List<File> existDirGetChildFiles(String path, boolean recursion) {
		return getDirFiles(path, recursion);
	}


	private static List<File> getDirFiles(String path, boolean recursion) {
		File dirFile = existRetFile(path);
		if (Objects.isNull(dirFile) || dirFile.isFile()) {
			return Lists.newArrayList();
		}
		File[] childrenFiles = dirFile.listFiles();
		if (ArrayUtil.isEmpty(childrenFiles)) {
			return Lists.newArrayList();
		}
		List<File> files = new ArrayList<>();
		for (File file : childrenFiles) {
			if (file.isFile()) {
				files.add(file);
			} else {
				if (!recursion) {
					continue;
				} else {
					List<File> fileList = getDirFiles(file.getPath(), recursion);
					if (!CollectionUtils.isEmpty(fileList)) {
						files.addAll(fileList);
					}
				}
			}
		}
		return files;
	}

	/**
	 * 根据path得到文件（File）
	 *
	 * @param path
	 * @return
	 */
	private static File getFile(String path) {
		File file = new File(path);
		return file;
	}

	/**
	 * 按照时间类型倒序排序
	 *
	 * @param files
	 * @param fileTimeZone
	 * @return
	 * @see
	 */
	public static List<Map.Entry<String, List<File>>> sortedByTimeDesc(List<File> files, FileTimeZoneEnum fileTimeZone) {
		Map<String, List<File>> treeMap = getFileListMap(files, fileTimeZone);
		List<Map.Entry<String, List<File>>> treeList = new ArrayList<>(treeMap.entrySet());
		treeList.sort((o1, o2) -> {
			Date o1parse = null;
			Date o2parse = null;
			try {
				SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
				o1parse = dateFormat.parse(o1.getKey());
				o2parse = dateFormat.parse(o2.getKey());
			} catch (ParseException e) {
				e.printStackTrace();
			}
			int compare = o2parse.compareTo(o1parse);
			return compare;
		});
		return treeList;
	}

	/**
	 * key是文件的时间,value是文件本身
	 *
	 * @param files
	 * @param fileTimeZone
	 * @return
	 * @see FileTimeZoneEnum
	 */
	private static Map<String, List<File>> getFileListMap(List<File> files, FileTimeZoneEnum fileTimeZone) {
		Map<String, List<File>> treeMap = new TreeMap<>();
		for (File file : files) {
			BasicFileAttributes attr = null;
			try {
				Path path = file.toPath();
				attr = Files.readAttributes(path, BasicFileAttributes.class);
			} catch (IOException e) {
				e.printStackTrace();
			}
			if (Objects.isNull(attr)) {
				continue;
			}
			// 创建时间
			Instant instant = null;
			switch (fileTimeZone) {
				case CREATE_TIME:
					instant = attr.creationTime().toInstant();
					break;
				case LAST_MODIFIED_TIME:
					instant = attr.lastModifiedTime().toInstant();
					break;
				case LAST_ACCESS_TIME:
					instant = attr.lastAccessTime().toInstant();
					break;
				default:
					throw new RuntimeException("时间类型错误");
			}
			String time = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss").withZone(ZoneId.systemDefault()).format(instant);
			if (treeMap.containsKey(time)) {
				List<File> fileList = treeMap.get(time);
				fileList.add(file);
				treeMap.put(time, fileList);
				continue;
			}
			ArrayList<File> arrayList = new ArrayList<>();
			arrayList.add(file);
			treeMap.put(time, arrayList);
		}
		return treeMap;
	}


	/**
	 * 按照时间类型顺序排序
	 *
	 * @param files
	 * @param fileTimeZone
	 * @return
	 * @see FileTimeZoneEnum
	 */
	public static List<Map.Entry<String, List<File>>> sortedByTimeAsc(List<File> files, FileTimeZoneEnum fileTimeZone) {
		Map<String, List<File>> treeMap = getFileListMap(files, fileTimeZone);
		List<Map.Entry<String, List<File>>> treeList = new ArrayList<>(treeMap.entrySet());
		treeList.sort((o1, o2) -> {
			Date o1parse = null;
			Date o2parse = null;
			try {
				SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
				o1parse = dateFormat.parse(o1.getKey());
				o2parse = dateFormat.parse(o2.getKey());
			} catch (ParseException e) {
				e.printStackTrace();
			}
			int compare = o1parse.compareTo(o2parse);
			return compare;
		});
		return treeList;
	}

	/**
	 * 转换文件大小
	 */
	public static String FormatFileSize(long fileS) {
		DecimalFormat df = new DecimalFormat("#.00");
		String fileSizeString = "";
		if (fileS == 0) {
			fileSizeString = "0.00B";
		} else {
			if (fileS < 1024) {
				fileSizeString = df.format((double) fileS) + "B";
			} else if (fileS < 1048576) {
				fileSizeString = df.format((double) fileS / 1024) + "KB";
			} else if (fileS < 1073741824) {
				fileSizeString = df.format((double) fileS / 1048576) + "MB";
			} else {
				fileSizeString = df.format((double) fileS / 1073741824) + "GB";
			}
		}
		return fileSizeString;
	}

	/**
	 * 删除文件
	 *
	 * @param filePath 文件
	 * @return
	 */
	public static boolean deleteFile(String filePath) {
		boolean flag = false;
		File file = new File(filePath);
		// 路径为文件且不为空则进行删除
		if (file.isFile() && file.exists()) {
			file.delete();
			flag = true;
		}
		return flag;
	}

	/**
	 * 文件名称验证
	 *
	 * @param filename 文件名称
	 * @return true 正常 false 非法
	 */
	public static boolean isValidFilename(String filename) {
		return filename.matches(FILENAME_PATTERN);
	}

	/**
	 * 检查文件是否可下载
	 *
	 * @param resource 需要下载的文件
	 * @return true 正常 false 非法
	 */
	public static boolean checkAllowDownload(String resource) {
		// 禁止目录上跳级别
		if (StringUtils.contains(resource, "..")) {
			return false;
		}

		// 检查允许下载的文件规则
		if (ArrayUtils.contains(MimeTypeUtils.DEFAULT_ALLOWED_EXTENSION, FileTypeUtils.getFileType(resource))) {
			return true;
		}

		// 不在允许下载的文件规则
		return false;
	}

	/**
	 * 下载文件名重新编码
	 *
	 * @param request  请求对象
	 * @param fileName 文件名
	 * @return 编码后的文件名
	 */
	public static String setFileDownloadHeader(HttpServletRequest request, String fileName) throws UnsupportedEncodingException {
		final String agent = request.getHeader("USER-AGENT");
		String filename = fileName;
		if (agent.contains("MSIE")) {
			// IE浏览器
			filename = URLEncoder.encode(filename, "utf-8");
			filename = filename.replace("+", " ");
		} else if (agent.contains("Firefox")) {
			// 火狐浏览器
			filename = new String(fileName.getBytes(), "ISO8859-1");
		} else if (agent.contains("Chrome")) {
			// google浏览器
			filename = URLEncoder.encode(filename, "utf-8");
		} else {
			// 其它浏览器
			filename = URLEncoder.encode(filename, "utf-8");
		}
		return filename;
	}

	/**
	 * 返回文件名
	 *
	 * @param filePath 文件
	 * @return 文件名
	 */
	public static String getName(String filePath) {
		if (null == filePath) {
			return null;
		}
		int len = filePath.length();
		if (0 == len) {
			return filePath;
		}
		if (isFileSeparator(filePath.charAt(len - 1))) {
			// 以分隔符结尾的去掉结尾分隔符
			len--;
		}

		int begin = 0;
		char c;
		for (int i = len - 1; i > -1; i--) {
			c = filePath.charAt(i);
			if (isFileSeparator(c)) {
				// 查找最后一个路径分隔符（/或者\）
				begin = i + 1;
				break;
			}
		}

		return filePath.substring(begin, len);
	}

	/**
	 * 是否为Windows或者Linux（Unix）文件分隔符<br>
	 * Windows平台下分隔符为\，Linux（Unix）为/
	 *
	 * @param c 字符
	 * @return 是否为Windows或者Linux（Unix）文件分隔符
	 */
	public static boolean isFileSeparator(char c) {
		return SLASH == c || BACKSLASH == c;
	}

	/**
	 * 下载文件名重新编码
	 *
	 * @param response     响应对象
	 * @param realFileName 真实文件名
	 * @return
	 */
	public static void setAttachmentResponseHeader(HttpServletResponse response, String realFileName) throws UnsupportedEncodingException {
		String percentEncodedFileName = percentEncode(realFileName);

		StringBuilder contentDispositionValue = new StringBuilder();
		contentDispositionValue.append("attachment; filename=")
				.append(percentEncodedFileName)
				.append(";")
				.append("filename*=")
				.append("utf-8''")
				.append(percentEncodedFileName);

		response.setHeader("Content-disposition", contentDispositionValue.toString());
		response.setHeader("download-filename", percentEncodedFileName);
	}

	/**
	 * 百分号编码工具方法
	 *
	 * @param s 需要百分号编码的字符串
	 * @return 百分号编码后的字符串
	 */
	public static String percentEncode(String s) throws UnsupportedEncodingException {
		String encode = URLEncoder.encode(s, StandardCharsets.UTF_8.toString());
		return encode.replaceAll("\\+", "%20");
	}

	/**
	 * 计算文件的MD5值
	 *
	 * @param file
	 * @return
	 */
	public static String getFileMD5(File file) {
		if (!file.isFile()) {
			return null;
		}
		MessageDigest digest = null;
		FileInputStream in = null;
		byte[] buffer = new byte[8192];
		int len;
		try {
			digest = MessageDigest.getInstance("MD5");
			in = new FileInputStream(file);
			while ((len = in.read(buffer)) != -1) {
				digest.update(buffer, 0, len);
			}
			return new BigInteger(1, digest.digest()).toString(16);
		} catch (Exception e) {
			e.printStackTrace();
			return null;
		} finally {
			try {
				if (in != null) {
					in.close();
				}
			} catch (Exception e) {
				e.printStackTrace();
			}
		}

	}

}
